President Donald Trump wants to “build a wall” between the U.S. and Mexico that, depending on your political allegiances, will either keep out dangerous undocumented immigrants or will serve little purpose outside of wasting taxpayers’ money.

One potential effect not receiving much media attention, however, would be felt by plants and animals local to the areas surrounding the border.

A continuous wall on the border between Texas and its southern neighbour will require 1840 km to be built in Texasalone. Estimates for the habitat loss are approximately 12-20 hectares (30-50 acres) per kilometre of wall.

Texas is at risk of losing up to 36 800 hectares (92 000 acres) of habitats, and that’s before even accounting for the roads that will be built to construct, maintain and monitor the wall, as will facilities like guard houses and tech hubs.

But at least the organisms outside of the building zone for the wall will be ok, right?

Not quite.

A wall at the U.S./Mexican border will cause something called habitat fragmentation. This occurs when something (usually either human constructions or geological events) separates what used to be a continuous ecosystem. Habitat fragmentation, in turn, causes population fragmentation, as animals become unable to travel to access the now separate ecosystem as they used to. This can have really severe effects on flora and fauna populations. If unable to travel to find mates, animal populations become inbred and unhealthy and can die out entirely.

Some plants and animals can adapt to new habitats, or live in slightly different ones, but others have specific needs only met by specific habitats. It’s possible for ecosystems to be completely eliminated by a construction like the wall, or for animals to become separated from the habitat they need to live in. Take for example the Tamaulipan thornscrub ecosystem, found near Southern Texas rivers. Agriculture and city expansions have already eliminated much of this ecosystem, and the remaining sites are directly in the wall’s planned path. With the elimination of this ecosystem will likely come the extinction of the endangered wildflower Physaria thamnophila.

The loss of one obscure wildflower may not seem like a big deal, but there are many more organisms potentially at-risk including ocelots, whiskerbushes, pygmy owls, desert bighorn sheep, jaguars, Sonoran pronghorns and javelinas.

Despite this, the construction is able to occur unhindered by environmental protections due to the REAL ID Act of 2005 that allows the secretary of Homeland Security to waive laws such as the Endangered Species Act and the Migratory Bird Treaty Act.

It’s hard to know for certain the effects a border wall would have on ecosystems, in part due to the difficulty in studying these areas. Researchers have reported being detained and harassed by Homeland Securityand “Minutemen civilian militias”while attempting to conduct fieldwork. However, one 2014 studyexamined an area in Arizona with border barriers and concluded that while they did affect native species, they had no effect on the movement of people across the border.

Don’t just take my word for it though. A reportdetailing the devastating environmental impacts of a border wall was published in the journal BioScience, signed by 2556 scientists from 43 countries. I think it’s fair to say that science has reached a consensus, and they’re not pro wall.